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Re: image drawing [message #26365 is a reply to message #26362]

Tue, 27 April 2010 19:19

dolik.rce
Messages: 1791
Registered: August 2008
Location: Czech Republic

Ultimate Contributor

raxvan wrote on Tue, 27 April 2010 17:50

Can i use safely multiple windows at the same time? (using threads)
How can i fire an event from a thread to another to update the window?

Yes, it is possible, actually even without threads. See GUI tutorial, paragraph 6 for description how. Usual approach to keep the GUI responsive is to have one thread handling GUI and a separate one for computations.

For updating the GUI from computation thread, there exist more possible ways. I usually use the dirty but simple one - I store a pointer to the part of GUI I need to update. Following example worked well for me when I needed to report the progress of computation to the user in a LineEdit:

thread__ LineEdit* ReportEditPtr;
void Report(String str,bool stamp,bool nl) {
	GuiLock __;
	(*ReportEditPtr)<<=(~(*ReportEditPtr)).ToString()+
	(stamp?FormatTime(GetSysTime(),"hh:mm:ss "):"")+str+(nl?"\n":"");
	(*ReportEditPtr).SetCursor((~(*ReportEditPtr)).ToString().GetLength()-1);
	(*ReportEditPtr).Refresh(); (*ReportEditPtr).Sync();
	}

And in the window constructor:

ReportEditPtr=&ReportLineEdit;

Hopefully someone will recommend you some cleaner way Smile

Honza

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